A key to ending the conflict in Afghanistan is to bring the Taliban to the bargaining table, a senior State Department official testified Wednesday on Capitol Hill.

“We have to change the calculus with the Taliban using both military and political means,” said acting Assistant Secretary of State Alice Wells.

Wells, who is the acting assistant secretary for South and Central Asia for the State Department, testified Wednesday in front of a House of Representatives joint subcommittee hearing on the $1.1 billion budget request for Afghanistan and Pakistan.

However, if lawmakers were looking for detailed answers on the way ahead, they instead got responses that were short on details and focused instead on larger strategic themes such as building regional partnerships and coaxing Pakistan to eliminate terrorist safe havens.

Echoing earlier comments made by Secretary of State Rex Tillerson, Wells told the subcommittee members that the conflict will likely end in a negotiated settlement between the Taliban and the Afghan government.

Withdrawal dates and announcements made by former President Barack Obama gave the Taliban no incentive to negotiate in recent years, she said.

Rep. Eliot Engel, D-N.Y., asked Wells why, if Tillerson was correct that neither the U.S. nor the Taliban will decisively win the war, the U.S. would send more troops there.

Wells said the previous stalemate meant the Taliban believed it could wait out the United States and win on the battlefield in their absence.

Rep. Mo Brooks, R-Ala., pressed Wells for an estimate on the timeline for success in Afghanistan.

“Ambassador Wells, are we talking years or are we talking decades?” Brooks said.

“Sir, I can’t answer that question,” Wells replied.

She said that Trump’s strategy does not “attach a calendar” to the conflict but the goal is to get the Taliban to the negotiating table as soon as possible.